The ECB's easy policy is having its "intended" effects, and the bank sees "no particular limit" to how it can use tools, Draghi said. He added that the central bank would "no doubt" intensify policy like its quantitative easing program, if needed.
"QE is there to stay. If needed, it could be recalibrated," Draghi said in response to a question after the speech.
His comments came a day after the ECB announced it would extend its 60 billion euro ($65.3 billion) a month bond-buying plan to at least March 2017. It previously cut its deposit rate further into negative territory by 10 basis points to -0.3 percent.
Markets had expected a deeper interest rate cut, and the euro soared Thursday after the announcement. In response to a question Friday, Draghi said the package was not "meant to address market expectations."